Apparatus for detecting trends in observed data



1 1945- H. ZIEBOLZ 2,390,569.

APPARATUS FOR DETECTING- TRENDS IN OBSERVED DATA Filed larch 24, 1942 3Sheets-Sheet 1 H. ZIEBOLZ Dec. 11, 1945.

3 Sheets-Sheet 2 Filed March 24, 19 42 I V w V v V W Mo fferberiziefiqf1945- E H. Z IEBOLZ 2,390,569

APPARATUS FOR DETECTING TRENDS IN OBSERVED DAIA Filed March 24, 1942 3Sheets-Sheet 3 Patented Dec. 11, 1945 amass- OFFICE APPARATUS FORDETECTING TRENDS IN OBSERVED DATA.

Herbert Ziebolz, Chicago, m., asslgnor it Askanla Regulator Company,tion of Illinois chi lll.,aoorpon- Application March 24, 1942, Serialiva isaozo 13 Claims.

This invention relates generally to an apparatus employable in carryingout an improved method of detecting a trend in observed data and has asa general object to provide a new and improved apparatus of thecharacter described.

It is known that if some variable characteristic of a plurality of likenatural objects, such as the height or weight of'men or women, the sizeor we ght of eggs or rain drops, and so forth, is subdivided into aplurality of equal ranges of a measure of that characteristic and rangedalong the abscissa axis of a graph, and the number of objects, whoseobserved characteristic falls within each range, are plotted asordinates on that graph, there results a typical distribution, forexample, the so-called normal or probability curve. I have discovered,that manufactured or processed articles or products, when similarlyobserved and the data plotted, produce a generally similar curve. A linedrawn through the apex or maximum value of such a normal curve andparallel with the ordinate axi indicates the true averageof the objectsor specimens observed and the curve shcwsthe distribution of thespecimens to one side or the other of the true average value.

The extremities of such a normal curve theoretically continue toinfinity and thu are approximately parallel with the abscissa axis. Theextremities also lie very close to the abscissa axis because therelative number of specimens that fall within the ranges remote from thetrue average are few. Since the normal curve is characterized by arather steep-sided midportion and rapidly. flattening extremities, eventhe number of specimens falling in range comparatively close to the trueaverage are few. It follows, therefore, that variation in the number ofspecimens falling in the more remote ranges would b comparatively minor,and such variations would be dimcult of detection by change in the graphat the flattened portions representing these ranges. If thus in amanufacturing operation the finished products are periodically sampledand tested only for theextreme over or under sizes, for examp e,

the possibility of detecting any deviation from desired or givenspecifications would be minute and very retarded.

I have found, however, that for a very small change inthe ordinate valueof, a normal curve at or near its flattened portion there is a verylarge change in the ordinate value of a point near the true averagevalueJnd that, likewise, there is a large lateral shift oi the trueaverage value or of the line drawn through the apex of the curve andparallel with the ordinate axis. his

a feature and object oi this invention to utilize the above fact inobserving or predicting trends in observed data and especially inmanufacturing operations, and to provide a new method of prediction andcontrol based on this fact.

'I'h'us if, in a manufacturing process, a first plurality of samples ofthe product are taken, checked as to the particular characteristic, andthe data plotted, as above mentioned, and subsequently another pluralityof samples of the prodnot are taken, checked as to the particularcharacteristic, and plotted to the same scale as the first plurality ofsamples, and the ordinate values of the two graphs for a common pointselected near the true average value of the first graph are compared, orif the true average lines of the two graphs are compared, there will beeasily observed even a slight change in the characteristic of theobjects. These observed ordinate values or positions of the true averageline will indicate a trend long before such trend could be detected orobserved by observation of the outsized products only. This method will,therefore, permit not only the prediction of the number of rejects, butwill forecast such increase in the number of rejects and permitcorrection or adjustment of the manufact ng process in due time to checkthe trend. v The tabulating and graphing of the data, when the method isapplied to a manufacturing or processing operation, might prohibitemployment of the method unless some means could be provided whereby thegraphs could be produced quickly and accurately, and by individualsother than highly skilled and trained statisticians. It is a furtherobject of this invention, therefore, to perrect a graphing apparatusparticularly designed for mechanically producing graphs of the characterdescribed.

A further object of the invention is to provide a relatively simple andinexpensive apparatus of the character described.

Other objects and advantages will become apparent from thefollowingdetailed description Fig. 3 is a top plan view of the machine,parts beingbrokenaway;

Fig.4isasectiontahenonthelinel-4offi8. and 1 l l i lga. gis'asectionalviewtakenonthelineH of Referring particularly to the drawings,the machine, there shown, is designed to be operated manually and isincorporated in a box-like metal casing orhousing i having a base II. Atop plate llof the casing has a rectangular sub-depressed portion lllc,the lower marginal edge Id of whichds subdivided into a plurality ofequal divisions ille representing ranges of some measare ofacharacteristic, dimension. or the like.

'Ihis marginal edge Hid may be considered as the presenting a chart facewith the slots i3 forming predetern'linedabscissa values.

Housed within the casing and projecting through and movablelongitudinally ineach slot i3 is an indicating finger l4 having anexposed head IS. The heads I! are centered with respect to the slots l3in order that they may represent the same properly spaced abscissavalues represented by the slots l3. These fingers are adapted tobeactuated by individual push buttons l8 at the front end of the machine.Therefore, after determining the ranges into which the variable ,orcharacteristic to be charted is to be subdivided, the ranges areassigned in consecutive order to the divisions Hie, the ranges beingsimilarly assigned to the push buttons 18 inasmuch as there is one pushbutton for each finger l4. Each actuation of a push button advance theassocia indicating finger a definite amount, all of the i dicators beingadapted to move through the plate I! are a plurality of parallel,

a sprocket on the shaft 31 like distances for each operation of a pushbutton, and all indicators having a common ordinate scale. The idea isto operate the indicators so that the position of each represents thenumber of units of data, that-is, items with a specific characteristic,falling into each range. The total number of actuations of the buttonswill represent the total number of objects .or specimens in the groupand variations can be determined by the positions of the indicatingfingers.

In this instance, the mechanism for operating the fingers is carried bya, rectangular frame Il mounted for longitudinal movement in guides l8The free ends of the levers 24 enga e a stop member 30 in the form of anangle fixed to the a 4 top plate l2. The stroke of all of the levers iscontrolled by means of an adjustment lever ll secured to a shaft 32extending across the and carrying stepp d plates or wing members II, onefor each of the levers 24. They are shown as having laterally bent ears34 forming the stop members to limit the downward movement of the levers24. The arrangement is such that the levers may be adjusted to havestrokes of three different lengths to advance the fingers l4 a greateror less distance as desired, depending upon the number of the articlesor data to be investigated. In Fig. 4, the adjusting member is set topermit the push buttons to have their minimum stroke so that the ratchetwheels 20 are turned the distance of only one tooth or notch at a time,

In this example, the machine is shown as embodying a totahzer or counter35, preferably having raised and reversed figures extending slightlyabove the chart face of the plate I 2 to permit figures to be printed orreproducedon a sheet, as will later be described. The counter is shownas being operated by a chain drive 38 connected to which carries ratchetwheels 38, one for each push button, adapted to be turned by dependingdetents 39 pivotally connected to the respective levers 24 and operativeto turn the shaft upon the return of the push buttons to their normalposition or after each push button has been actuated. The arrangement issuch that each ratchet wheel 38 is advanced the d stance of one tooth,regardless oi the adjusted stroke of the levers 24. Also, the counterwill be advanced one unit each time any one of the push buttons isoperated.

After all of the data desired to be investigated has been tabulated to.produce a curve for comparison with a normal or previous sample curvesimilarly produced, the indicating heads I! may be observed on the chartface. record of the curve outline, produced by the relative positions ofthe indicating fingers in their respective slots, may be made for recordor com-.

parison purposes by placing a graph paper or other sheet 40, facedownward, on the machine with a sheet of carbon paper between it and thech'art face, and an imprint may be made by at the opposite sides of thecasing and comprises j which the bottom and side edges of the sheetabut. The heads It, as well as the figures on the a series of screwthreaded shafts is which oper- -22 cosctingwith spring urged clutchmembers 23 onthe front ends of the screw shafts is projecting thi'oughthe front end of they frame member li/ The push buttons it are shown asbeing con-' nected to operate pivoted levers 24 mounted on a {importingplate 26 within the casing and these vers carry pivotally connectedoperating pawlsfIl guided for vertical movement in a perforated channelmember 11 extending across the casing.

The buttons are normally held in the position shown by small compressionsprings 28 mounted on pivoted links or guide rods 29, also extendingthrough openings in the transverse channel 21.

clamping pressure applied to the back of the sheet 40. This ispreferably done by a hinged cover plate 4| adapted to be swung down overthe back of the entire graph sheet. In order to align ,the sheet 40properly to be imprinted, the top'of the housing III has a depressedportion Ina providing front and side raised edges llb against 4| may bemade of glass or other transparent material and have a standard curvedrawn on it for the. same purpose. In either event, the glass shouldalso carry the ordinate and abscissae similar to those shown on thesheet 40.

When the desired data has been tabulated for Also, a permanent the cover4|, which fits within the edges aseasoo spring-urged friction clutchelements 43 at its opposite end projecting beyond the frame memher II tobe engaged, in this shifted position by manually operable frictionclutch elements ll so that the screw shafts may be turned in the reversedi tion to returnthe fingers or pointers to their; zero positions. Inthis example, each driving clutch element H is mounted on a shaft 48carrying a bevel gear It and all of the bevel gears 48 are driven by ashaft 4'! carrying driving gears 48 and the shaft is adapted to beoperated by a suitable crank is accessible from the outside of themachine. The friction clutch elements permit slippage in those instanceswhere the indicator has been returned to zero prior to the time that allof the others have reached zero. In this instance, the crank end and itsoperating shaft is adapted to be removably connected to the shaft 41 topermit the casing to be dismantled from the base of the machine andafiord access to the operating parts.

In some instances, it is also desirable to operate the counter I!manually and move it to its zero position. for the next tabulatingoperation. This may be done by any suitable means. but there is shown anoperating spindle 50 having a knurled knob ll accessible at one side ofthe casing and adapted to be removably connectedto the countershaft,likewise to permit the machine casing to be removed.

In some cases, it is highly desirable to operate the machine from adistance, especially in checking up machine operations, size or lengthsof parts in plant operations, etc., so that the opright of the normalcurve printed on the sheet.

If the recorded data represents sizes, for example, the abscissa willshow over-sizes, when they appear to the right of the ordinate whichpasses" through the peak of the normal curve. In this particularinstance, one can immediately conclude that the trend is towardover-size. and this may be interpreted in terms of accuracy of a machineor an individual mechanic, for example. Remedial measures may be takenand the results determined by investigation of another group of theparts before a machine has so far worn or its adjustment so fardisturbed'as to produce an excessiv number of worthless .parts.

The ready detection of this trend, long before the consequences thereofare apparent, will be clearly understood-from a more detailed study ofthe graphs of Fig. 2. In a manufacturing operation, for example, anyproduct falling within the first two, and perhaps even the first three,squares to either side of the line passing through the apex of thebroken line curve would come within the permissible limits of dimensionsof the product. If size is the characteristic being observed. the numberof over-size products is represented by the area beneath the flattenedportion of the curve beyond the third square to the right of the linethrough the apex of the broken line curve. The number of over-sizeproducts thus is extremely small, and-it is even conceivover-sizedproducts. Thus, to detect a changing condition or trend in the size ofthe products by checking merely for over-size products would not onlyprove difllcult, but might in certain instances even give an erroneousindication. If, on the contrary, the method herein disclosed is followedand some abscissa value near the line through the apex of the brokenline curve be selected,

erator may be located in the shop or plant and 4s and the ordinatevalues of the graphs then comthe indicating mechanism or machines placedin the ofllces of an executive. For that purpose, the machine isdesigned to be operated electrically. Herein, there is shown a series ofsolenoids 52,

pared, a pronounced indication of even the slightest trend will be had.By way of example. there might be chosen for this common abscissa pointthe outside margin of the second square to one for each screw shaft,arranged on the base the right of the line through the apex of the H ofthe casing and having armatures 53 mechanically connected to thelowerends of the guide rods 28 so that, when the solenoids ore energized, adownward impulse will be im arted to each lever 24 in the same manner asif they had been manually actuated by the push buttons it. The solenoidsare connected by a suitable electric cable 54 to a portable push buttonblock or panel II carrying the same number of push buttons 83 as areembodied in the machine. These push buttons, of course, actuate switchesto close the circuits to the respective solenoids. It will, of course,be understood that the electric circuits are connected to a suitablesource of current.not shown. Referring aga n to the graph sheet'on whichthe indicating data is adapted to be printed or reproduced by the methodhereinbei'ore described, it will be understood that a normal ordistribution curve may be previously printed on each sheet so that theexpected curve produced b the investieation of a group of statistics orob erved data 1 will be superimposed thereon and will coincide with itif there is no abnormal tendency or'trend in the data. Preferably,however, the sheets are broken line curve. This line in Fig. 2 is seento intersect the broken line curve one and one-half squares up from thebottom of the chart. This same line intersects the curve indicated bythe circles almost six squares up from the bottom of the chart, a changeof four and one-half squares in the ordinate value of the curve at thatparticular abscissa point. Thus, the change is so promote the eiilciencyof manufacturing processes and business operations.

Obviously, the present inventionis not restricted to the particularembodiment thereof herein shown and described. Moreover, it is notessential that all of the features of the invention be used coniointly.since they may be employed advantageously in various combinations andaubcombinations. 4

What is claimed is:

l. Indicating apparatus comprising, in combination, a tabulating machinehaving a chart face presenting a plurality of parallel slots; indicatingfingers having heads projecting through said slots and exposed on thechart face; screw threaded shafts connected to operate said indicatingfingers to move them in said slots; a push button and ratchet memberconnected to each of said screw threaded shafts to actuate the same;clutch members for disconnecting the push buttonsffrom the shafts; andmeans to rotate all of the shafts when disconnected from said pushbuttons.

2. Indicating apparatus of the character described comprising, incombination, a casing hav-' ing an upper chart face presentinglongitudinal slots therein; indicating members having heads projectingthroughthe slots and exposed on the chart face; screw threadedshaftsvconnected to operate the indicating members; manuallyoperthereof, and means rigidly interconnecting all of said step membersfor simultaneous actuation and like positioning.

' 3. 'A graphing device comprising, in combinaoutlining a chart face onemarginal edge of which is subdivided into a plurality of equal divisionsadapted to represent ranges in themeasure. of a characteristic, this edgrepresenting the abscissa axis of a coordinate axis graph the ordisslot, independent means associated witheach of said indicating membersfor advancing the indicating member step-by-step along the slot throughwhich it projects, actuating means for each independent meansoperatively associated therewith to advance an associated indicatin!member an amount equal to the advance imparted to any other indicatingmember by similar actuation of any of the other actuating means, and ameans common to all of said indicating members operable to impartcontinuous movement to all of said indicating members simultaneously.

5. A graphing device comprising, in combination; a casing having in thetop wall thereof a plurality of parallel equally spacedslots.'indicating members-housed in said casing and projecting onethrough each of the slots, means for each of said indicating members foradvancing the same longitudinally of the slot including supporting andadvancing means, actuating means a and a clutch for connecting ordisconnecting said able. actuating levers connected to impart step bystep rotation to said screw threaded shafts; a plurality-of stopmembersfor each actuating le- -ver selectively interposable in the pathof said lever to vary the permissible actuating stroke tion, a casinghaving in one wall thereof means supporting and advancing means fromsaid actuating means, and a means common to all of said supporting andadvancing means including friction clutches engaged when said firstmentioned clutches are disengaged for operating all the indicatorssimultaneously. i

6. A graphing device comprising, in combination, a casing having in onewall thereof a plurality of parallel equally spaced slots adapted torepresentmidpoints in ranges in a measure of a characteristic, means forindicating the relative number of unitsof data falling into each rangeincluding a plurality of indicating members housed in said casing andprojecting one through each of the slots, the exposed tip of eachindicating member being centered in the slot, a screw nate axis 01'-which is represented by a marginal edge of the chart face at rightangles to the first mentionededge, said wall having formed therein aplurality of slots each parallel with the last, named marginal edge andeach located at the midpoint of one of said divisions, indicatingmembers housed in said casingprojecting onethrough each of the slots andhaving a head exposed onthe chart face,.a screwmember for'actuating eachof the indicating members, a manually operable actuator for each of thescrew members, a clutch associated with each screw member and actuatorto connect the screw member to the actuator for movement of the-indicator by the actuator and to disconnect the screw member formovement of the indicatorindependently of the actuator. and a singlemeans operativeiy associated with said screw members for vsimultaneously moving all of the indicators when the actuators have beendisconnected from the screw members. i

4. A graphing device comprising, in combination, a casing having in onewall thereof means outlining a chart face one marginal edge of .which issubdivided into a pluralityof equal divisions of the chart faceat' rightangles to the first mentioned edge representing the ordinateaids of alast named marginal edge -and each located'at the midpoint of one ofsaid divisions, indicating members housed in said casing and projectingmember for each of said indicating members providing a support thereforand connected thereto to advance the same upon rotation of the screwmember, a clutch element nonrotatably secured -to each end of each screwmember, the clutch elements at one end of all of the screw members beingfrictional clutch elements, individual actuating means for each of saidscrew members including a clutch element, a common actuating meansdisposed at the end of said casing opposite said individual actuatingmeans and having a plurality of frictional clutch elements adapted to besimultaneously driven and disposed in axial alignment with and adjacentto the frictional clutch elements carried on said screw members, and aframe supporting'all of said'screw members', said frame being ,shiftablein the direction posite direction disconnecting the screw mem- 1 adaptedto represent rangesinthe measure of a characteristic. this edgerepresenting the abscissa, axis of a coordinate axis graph. a marginaledge one through each of the slots, the exposed tip at each indicatingmember beingcentered inv the of the'screw members, shift of the frame inthe one direction connecting the screw members through one set of clutchelements to said individual actuating means for step-by-step advance ofthe indicating members as the corresponding actuating means areactuated, and shift in the opbers from said individual actuating meansand connecting the same to said common actuating meansthroughthe'frictional clutch elements for.

simultaneous movement of said indicating members.

'7. A graphing device comprising, in combina- I, tion, a casing havingin one wall thereof a plurality of parallel, equally'space'd slotsadapted to represent midpoints in ranges in a measure of acharacteristic, means for indicating the relative number of units ofdata falling into each range including aplurality of indicating membershoused in said casing and projecting one through each of the slots, theexposed tip of each indimember step-by-step along the slot through whichit projects, and actuating means for each independent means operativelyassociated therewith to advance an associated indicating member witheach actuation of said actuating means.

8. A graphing device comprising, in combination a casing having in onewall thereof more than two parallel, equally spaced slots adapted torepresent midpoints in ranges in a measure of a characteristic, meansfor indicating the relative number of units of data falling into eachrange including a plurality of indicating members housed in said casingand projecting one through each of the slots, the exposed tip of eachindicating member being centered in the slot, a screw member for each ofsaid indicating members providing a support therefor and connectedthereto. to advance the same upon rotation-of the screw member,actuating means for each of said screw members, and a clutch for each ofsaid screw members for engaging or disengaging the same from theactuating means.

9. A graphing device comprising, in combination, a casing having in onewall thereof a plurality of parallel, equally spaced slots adapted torepresent midpoints in ranges in a measure of a characteristic, meansfor indicating the relative number of units of data falling into eachrange including a plurality of indicating members housed in said casingand projecting one through each 'of the slots, the exposed tip of eachindicating member being centered in the slot, a screw member for each ofsaid indicating members providing a support therefor and connectedthereto to advance the same upon rotation of the screw member, a clutchelement nonrotatably secured on one end of each screw member. actuatingmeans for each of said screw members including a cooperating clutchelement, and a frame carrying all of said screw members, said framebeing shiftable in the direction of the screw members simultaneously toeffect engagement or disengagement of all of said clutch elements.

10. A graphing device comprising, in-combination, a casing having in onewall thereof means outlining a chart face one marginal edge of whichisfisubdivided into a plurality of equal divisions adapted to representranges in the measure of a haracteristic, this edge representing theabscissa of a coordinate axis graph,v a marginal edge of the chart faceat right angles to the first mentioned edge representing the ordinateaxis of a coordinate axis graph, said wall having formed therein aplurality of slots each parallel with the last named marginal edge andeach lbcated at the midpoint of one of said divisions, indicatingmembers housed in said casing and projecting onethrough each or theslots, the exposed tip of each indicating member being centered in theslot, independent means associated with each of said indicating membersfor advancing the indicating member step-by-step along the slot throughwhich it projects, and actuating means for each independent meansoperatively associated therewith to advance an associated indicatingmember an amount equal to the advance imparted to any other indicatingmember by similar actuation of any of the other actuating means.

11. In a graphing device having a casing with a, plurality of parallel,equally spaced slots in one wall thereof, indicating members housed insaid casing and projecting one through each of the slots and meansassociated with each indicating member for moving the same step-by-stepalong the slot including actuating means having an operative forwardstroke and an idle return stroke,

a plurality of stop means for each actuating means selectivelyinterposable in the path of said actuating means variably to limit thepermissible operative strok thereof and thus to vary the advance of theassociated indicating member with each actuation of the actuating means,and means rigidly interconnectin all of said stop members forsimultaneous and like interposition in the path of said actuating means.

12. A graphing device comprising, in combination, a casing having in thetop wall thereof a plurality of parallel, equally spaced slots,indieating members housed in said casing and projecting one through eachof the slots, a screw threaded shaft for each of said membersoperatively associated therewith to move the same longitudinally of theslot upon rotation of the shaft, means for individual and step-by-stepactuation of said members including a push button and ratchet member foreach of said screw shafts,

a clutch for each screw shaft operable to connect or disconnect theshaft from its push button and ratchet member, means for actuating allof said clutches simultaneously, and means for rotating all of saidscrew threaded shafts simultaneously.

13; A graphing device comprising, in combination, a casing having in.the top wall thereof a plurality Of parallel, equally spaced slots,indicating members housed in said casing and projecting one through eachof the slots, a screw threaded shaft for each of said membersoperatively associated therewith to move the same longitudinally of theslot upon rotation of the shaft, meansfor individual and step-by-stepactuation of said members including a push button and ratchet member foreach of said screw shafts, a clutch for each screw shaft operable toconnect or disconnect the shaft from its push button and ratchet member,means for rotating all of said screw threaded shafts simultaneously andin either direction including a common drivin member and a clutch foreach shaft for connecting the same to or disconnecting the same fromsaid common driving member, and common means for actuating the twogroups of clutches connecting the one while disconnecting the other.

- a HERBERT ZIEBOLZ.

